Electric switch construction



Oct. 17, 1939. w MQDRACK 2,176,538

ELECTRIC SWITCH CONSTRUCTION Filed Nov. 22, 1938 I l M J ///////l///l/////// IN VEN TOR.

ATTORNEYS.

Patented Oct. 17, 1939 2,176,538

UNITED STATES PATENT OFFICE ELECTRIC SWITCH CONSTRTJCTION William H. Modrack, Toledo, Ohio Application November 22, 1938, Serial No. 241,859

6 Claims. (Cl. 200- 82) This invention relates to electric switch con- The base I is also provided with a central struction, the primary object of the invention cut-out portion II that extends through the bore. being to provide a pneumatically controlled Mounted for sliding movement within the bore switch which will be actuated by the weight of of the base H], is a rod [2 that carries pistons l3 5 a vehicle passing over the control means thereof, and H! at its ends, the pistons being of diameters 5 for completing a circuit to operate a suitable to closely fit within the bore of the body portion. audible or visible signal, as conditions may re The coiled springs 9 are of lengths to engage the quire. outer ends of the pistons I3 and M, to normally An important object of the invention is to hold the pistons in the position as shown by 10 provide a switch of this character which will, Figure 2 of the drawing. 1 with a single operation, operate to produce a Secured to the base [0, is a plate I5 which is double signal through the simple compression constructed of insulating material, the plate i5 and release action of the device. being held in position by means of the screws I6.

Another important object of the invention is to This plate l5 carries the contact member l1 provide a signal which will be operated by a which has connection with the wire i8 leading 1 switch embodying but few parts, and one which through an opening in the side wall of the box will be exceptionally cheap to manufacture, due like body portion 5. In circuit with the base In, consideration having been given to the strength is a plate I 9 to which the wire which also leads and durability of the structure. through an opening in the side wall of the box- 20 With the foregoing and other objects in view, like body portion 5, is connected. These wires i8 which will appear as the description proceeds, and 2!], of course lead to a signal not shown, and the invention resides in the combination and arwhich is necessarily in circuit with a suitable rangement of parts and in the details of consource of electricity supply. struction hereinafter described and claimed, it Secured to the contact member I1, is an inbeing understood that changes in the precise emverted U-shaped contact member indicated at 25 bodiment of the invention herein described, may 2|, the arms of the contact member 2! being of be made within the scope of what is claimed, lengths to extend into the path of travel of the Without departing from the spirit of the invenpistons l3 and M, as the pistons move longition. tudinally of the bore of the base IU. Referring to the drawing: Connected with each fitting 6, is a rubber tube 30 Figure 1 is a side elevational view of a switch 2| which in turn has connection with a rubber constructed in accordance with the invention. sack 22, the sacks 22 being closed at their outer Figure 2 is a vertical sectional view through ends. the switch. A cover plate indicated by the reference char- 5 Figure 3 is a plan view of the switch, the cover acter 23 closes the top of the box-like body porplate thereof having been removed. tion, and affords means whereby the various ele- Referring to the drawing in detail, the switch ments of the switch may be readily inspected or comprises a box-like body portion indicated genrepaired.

erally by the reference character 5, the body por- The operation of the switch is as follows: Astion being formed with openings in its end, into suming that the compressing action is directed 40 which the unions 6 are extended. to the body portion of the switch from the right As shown, these unions 6 are provided with side rubber tubing. The air sealed within the bores l which have enlarged end portions 8 protubing forces the piston to the left side of the viding seats for the coiled springs 9 which are body portion until the inner face of the right- 46 of lengths to extend appreciable distances within hand section or piston has made contact on the the body portion. right-hand side of the inverted U-shaped contact Positioned within the box-like body portion 5, member 2i, thereby completing the circuit to the is the switch base indicated by the reference signal which is in circuit with the switch, and character II], the switch base being of a length which is not shown in the present drawing.

50 to closely fit against the end walls of the body The signal remains operative for the duration 50 portion 5. The base i0 is provided with a longiof a few seconds, by which time the air has distudinal bore that has its ends threaded toresipated slowly through the space between the ceive the threaded ends of the unions 6, which piston and the cylinder wall, due to the fitting secure the base [0 in position against lateral of the piston to produce this result. The coiled movement. spring at the extreme left has been contracted 55 under this pressure. Meanwhile the air after a few seconds time has seeped through the space between the cylinder wall and the piston to such an extent that the coiled spring at the left functions and expands to its normal length, releasing the piston from its connection with the contact member 2! the piston returning to about its normal position. Up to this point the rubber tube 2| is still in its compressed position. However, upon the release action of the tube the air is drawn back, bringing the piston to the right side of the body portion, contracting the righthand coiled spring to such a point that the inner face of the left section of the piston hasmade its contact on the left side of the inverted U-shaped contact member 2| for another few seconds of time making the second separate and distinct signal. Meanwhile, the air has again seeped through between the cylinder wall and the piston, equalizing the pressure, the right-hand coiled spring expanding to its normal shape forcing the piston away from the contact with all parts returning to their normal or inactive positions. When the compression is entirely released the piston returns to its normal position by the action of the coiled springs at both ends of the rod 12. It will of course be understood that if the compression action comes from the left side of the body portion, or through the tube connected with the union at the left side of the body portion, the action as described will be reversed.

What is claimed is:

1. A pneumatically controlled switch comprising a switch base having a longitudinal bore, a contact member extending into the bore at a point intermediate the ends thereof, pistons operating within the bore, a rod connecting the pistons, means for directing air under pressure to either end of the bore moving the pistons to complete a circuit with the contact member, and yieldable means for normally urging the pistons to their inactive positions.

2. A pneumatically controlled switch comprising a switch base having a longitudinal bore, and having a central cut-out portion extending to the bore, pistons operating in the bore, a con.- tact member extending into the cut-out portion and disposed in the path of travel of the pistons, and means for directing air under pressure to the pistons moving the pistons longitudinally of the bore to engage the contact member completing a circuit, and springs for urging the pistons to their normal positions.

3. A pneumatically controlled switch comprising a base having a longitudinal bore, a contact member extending into the bore, spaced pistons operating in the bore, means for directing air under pressure to either end of the bore, moving the pistons longitudinally of the bore, said pistons adapted to engage the contact member completing a circuit, and means for returning the pistons to their normal positions when the air pressure is released.

4. A pneumatically controlled switch comprising a base having a longitudinal bore, pistons operating within the bore, a flexible tube connected with each end of the base and communicating with the bore and adapted to direct air under pressure to the bore moving the pistons when the flexible tube is compressed, and a contact member extending into the bore and adapted to be engaged by the pistons completing a circuit.

5. A pneumatically controlled switch comprising a base having a longitudinal bore, a rod having pistons at its ends, operating in the bore, a contact member extending into the bore and disposed in the path of travel of the pistons to be engaged by the pistons completing a circuit, and flexible tubes connected with the ends of the base and adapted to direct air under pressure to the bore moving the pistons longitudinally of the bore, when the flexible tube is compressed, and springs for returning the pistons to their normal positions.

6. A pneumatically controlled switch comprising a base, pistons operating in the base, a contact member disposed in the path of travel of the pistons, and adapted to be engaged by the pistons, completing a circuit, flexible tubes connected with the base and adapted to direct air under pressure to the pistons when the tubes are compressed, and means for returning the pistons to their normal positions.

WILLIAM H. MODRACK. 

